The part you are looking for is the headlight assembly. I believe the tab which is broken on yours you can see sticking up in this image:
In my humble opinion, you are going to be better off finding an aftermarket set off of eBay or Amazon which will fit your truck. This way they match exactly. You could also try a pick-a-part or junk yard for your exact replacement, but seeing as how new the truck is, that may be a little bit hard.
Something to think about (which I don't see you mentioning) is how did the tab get busted in the first place? If it something obvious like a hit to the headlight, then it's a no brainer. If, you are not sure how it happened, you'll want to figure it out before you replace it. If you don't and just replace it, you might end up breaking the tab on the new one as well. This could be really important if there's an alignment issue with where everything goes together. Just a suggestion.
Note: If you are having trouble with your GoogleFu, here's a Google Search which I used to find it along with an image.